package main

import "fmt"

func GetSum() func(int) int {
	var sum int = 0
	return func(x int) int {
		sum = sum + x
		return sum
	}
}
func add(num1 int, num2 int) int {
	defer fmt.Println(num1) //3
	defer fmt.Println(num2) //进入栈中  栈的特点是 先进后出2
	var sum int = num1 + num2
	fmt.Println(sum) //先执行1
	return sum       //4
}

func main() {
	f := GetSum()
	fmt.Println(f(1))
	fmt.Println(f(2))
	fmt.Println(f(3))
	fmt.Println(add(30, 60))
}